Let GPS Find You
June 27, 2013 § Leave a comment
Remember those sci-fi movies in which characters are tracked by putting a small device on the object they always carry (e.g. their clothes)? Unless the character figures it out that there’s that little object clinging to his body, he will never get away from the people hunting for him. Or just remember those things they injected to the tributes in The Hunger Games. It might look deadly but it’s just something the host can use to track where the tributes are in the very large arena.
It may sound weird, useful, something you might want to own yourself. Here’s the good news: you can have it. Or at least something with the same capabilities, because usually, it’s a feature in phones. This little object I am talking about is more commonly called GPS.
What it Means
A global navigation satellite system (GNSS), the Global Positioning System (GPS) is created by the United States Department of Defense and managed by the United States Air Force 50th Space Wing. Aside from being the only fully useful GNSS in the world, it is free to use, and often it is used by kinds of people for navigation purposes. It uses a constellation of between 24 and 32 Medium Earth Orbit satellites that send precise microwave signals, allowing GPS receivers to find their current location, time, and their velocity. Its official name is NAVSTAR GPS. Although NAVSTAR is originally not an acronym, a few acronyms have been created for it. A GPS receiver should be able to get signals from about 10 satellites at a time in ideal circumstances, but far fewer can be picked up reliably in most real-world conditions.
Uses of GPS
Although we all know that GPS is for locating something or someone, that’s just the very general idea of it. Some specific uses of GPS are listed here.
The military applications of GPS span many purposes:
- Navigation: GPS allows soldiers to find goals in the dark or in unfamiliar territory, and to coordinate the troops and supplies’ movement. The GPS-receivers that commanders and soldiers use are respectively called the Commanders Digital Assistant and the Soldier Digital Assistant.
- Target tracking: Various military weapons systems use GPS to track potential ground and air targets before they are flagged as hostile.These weapon systems pass GPS co-ordinates of targets to precision-guided munitions to allow them to engage the targets accurately. Military aircraft, particularly those used in air-to-ground roles use GPS to find targets (such as, gun camera video from AH-1 Cobras in Iraq show GPS co-ordinates that can be looked up in Google Earth).
- Missile and projectile guidance: GPS allows correct targeting of various military weapons including ICBMs, cruise missiles and precision-guided munitions. Artillery projectiles with embedded GPS receivers able to withstand accelerations of 12,000G have been developed for use in 155 mm howitzers.
- Search and Rescue: Downed pilots can be located faster if they have a GPS receiver.
- Reconnaissance and Map Creation: The military use GPS extensively to aid mapping and reconnaissance.
- The GPS satellites also carry a set of nuclear detonation detectors consisting of an optical sensor (Y-sensor), an X-ray sensor, a dosimeter, and an Electro-Magnetic Pulse (EMP) sensor (W-sensor) which form a major part of the United States Nuclear Detonation Detection System.
Many civilian applications benefit from GPS signals, using one or more of three basic components of the GPS: absolute location, relative movement, and time transfer.
Assisting the GPS unit
GPS was designed around devices operated outdoors, and that’s why there’s room for improvement. This is where AGPS, and services that can also use GPS data, come in. A standalone GPS is most often used outdoors, where there’s often a good line of sight to several satellites. Because its most common use is in an automobile, the receiver’s position doesn’t change while it’s powered off; and it’s used over time, so an initial fix on location is often less critical.
GPS in Westeros and GPS Monsters
Imagine if there’s GPS in Westeros, the fictitious world created by George R.R. Martin in his best-selling A Song Of Ice And Fire series. To be sure, the Starks will easily find Arya, saving a ton of energy and time from those who want a ransom in exchange of her. But of course, the Lannisters would buy lots of GPS and would secretly put this in their enemies’ garbs. So, nope. Maybe not a good idea after all. ASOIAF readers will thank GRRM for not setting the story in a modern world where you can get a number of GPS more than you’d know what to do with it.
Although no one can deny that GPS is an immense help, it also takes away the freedom of some people and has also the ability to make us GPS monsters, the kind of people who’d want to know where exactly their boyfriend or girlfriend is. Be honest, who’d want such a partner? Not only it can be suffocating in a relationship, we have to admit that it’s creepy too. So know how not just how to use GPS. The “when” and “why” are important as well.